Nosnibro is technically correct saying an SRN is the lowest level on Nursing. this as been so since the demise of the SEN and the introduction of Health Care assistants or workers with similer titles.
HOWEVER the SRN of today is in most cases is at least BSc or Bachelor of Nursing, those that are not will probably have qualified under the old Hospital based system and have many years experience.
Manny SRNs will also have Post Graduate qualifications including PhD's and MSc's which academically are higher qualifications than a medical Doctor who may only have a Bachelors qualification such as MBBCh – Bachelor of Medicine and Surgery MBChB – Bachelor of Medicine and Surgery MBChirB – Bachelor of Medicine and Surgery MBBS – Bachelor of Medicine and Surgery .